#include "Base64.h"
#include <iostream>
 
static const std::string base64_chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";


static inline bool is_base64(unsigned char c) {
  return (isalnum(c) || (c == '+') || (c == '/'));
}

std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {
  std::string ret;
  int i = 0;
  int j = 0;
  unsigned char char_array_3[3];
  unsigned char char_array_4[4];

  while (in_len--) {
    char_array_3[i++] = *(bytes_to_encode++);
    if (i == 3) {
      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
      char_array_4[3] = char_array_3[2] & 0x3f;

      for(i = 0; (i <4) ; i++)
        ret += base64_chars[char_array_4[i]];
      i = 0;
    }
  }

  if (i)
  {
    for(j = i; j < 3; j++)
      char_array_3[j] = '\0';

    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
    char_array_4[3] = char_array_3[2] & 0x3f;

    for (j = 0; (j < i + 1); j++)
      ret += base64_chars[char_array_4[j]];

    while((i++ < 3))
      ret += '=';

  }

  return ret;

}

std::string base64_decode(std::string const& encoded_string) {
  int in_len = encoded_string.size();
  int i = 0;
  int j = 0;
  int in_ = 0;
  unsigned char char_array_4[4], char_array_3[3];
  std::string ret;

  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
    char_array_4[i++] = encoded_string[in_]; in_++;
    if (i ==4) {
      for (i = 0; i <4; i++)
        char_array_4[i] = base64_chars.find(char_array_4[i]);

      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

      for (i = 0; (i < 3); i++)
        ret += char_array_3[i];
      i = 0;
    }
  }

  if (i) {
    for (j = i; j <4; j++)
      char_array_4[j] = 0;

    for (j = 0; j <4; j++)
      char_array_4[j] = base64_chars.find(char_array_4[j]);

    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
    char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

    for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
  }

  return ret;
}

std::string Encrypt(std::string oriString)
{
        string finalString="";
        //printf("oriString=%s\n",oriString.c_str());

        char numChar;
        int retEncrypt;
        srand((int)time(0));
        int ranDomNum=randomNum(100);
        ranDomNum=20;
  
        reverse(oriString.begin(),oriString.end());

        //string tempOriString="";
        //tempOriString.assign(oriString.rbegin(),oriString.rend());
 
        //printf("tempOriString=%s\n",tempOriString.c_str());
        for(int i = 0;i<oriString.length();i++)
        {
                numChar = oriString.at(i);
                retEncrypt  = (int)numChar;
                retEncrypt = numChar^(ranDomNum%32);
                finalString+=(char)retEncrypt;
        }
        finalString+=(char)ranDomNum;
        string encoded = base64_encode(reinterpret_cast<const unsigned char*>(
		finalString.c_str()),finalString.length());
        return encoded;
}
std::string Decrypt(std::string oriString)
{
        string decodeString  = base64_decode(oriString);
        string finalString="";
        int ranDomNum =(int)decodeString.at(decodeString.length()-1);
        int numChar;
        int retEncrypt;
        cout<<"ranDomNum="<<ranDomNum<<::endl; 
        printf("decodeString.length()-1=%d\n",decodeString.length()-1);
        for(int i = 0;i<decodeString.length()-1;i++)
        {
                numChar = (int)decodeString.at(i);
                retEncrypt = numChar^(ranDomNum%32);
                finalString+=(char)retEncrypt;
        }
        //string tempString="";
        //tempString.assign(finalString.rbegin(),finalString.rend());
        reverse(finalString.begin(),finalString.end());
//      printf("tempString=%s\n",tempString.c_str());
//        printf("finalString=%s\n",finalString.c_str());
        return finalString;
}
